Crimson Terror Ants

Not much varies the two Terror Ants. The only difference is that the Crimson Terror Ant has more health than normal Terror Ants and therefore harder to kill. They cannot shoot acid like Terror Ants can and appear later in the game at roughly mission 13 Crimson. They then appear in various missions after that. Crimson terror ants tend to travel in slightly larger swarms than the normal kind and it is easy to get surrounded and die. Good weapons for killing these ants are rockets (e.g. Cascade 2) flamethrowers (e.g. magma thrower) and grenade launchers. Basically, you need weapons that can wipe out lots of crimson terror ants at a time.

Tips and Strategies
For the level Crimson, there are three waves of enemies. The first comes from the beach directly infront of you. The second comes opposite that, and the third wave comes from the hills. Wipe out the first wave using only your weapons. Leave one ant remaining (kill your allies so that they don't shoot it.) If you do accidently kill the last ant in a mave it will immediately trigger the next wave so prepare yourself in this time. For the second wave, get into the tank. It is just like a grenade launcher plus extra armor so use it to your advantage. Be careful not to drive it into the water or it will get destroyed instantly. If you do manage to survive the wave with the tank use it for the next wave aswell.

A tip for killing ants in the level Crimson is to swim into the water. You cannot shoot whilst swimming, and neither can the ants bite you. What you can do it wait for the ants to crawl under you when in the water. You will be able to stand on them from time to time which gives you short opportunities to shoot them. Only use this technique as a last resort because it takes an extremely long time to kill all the ants.

Many players use the level Crimson as a good level to get armor, to make them stronger when fighting tougher levels. This is because it is a level where there are big swarms of bugs, and it is quite an easy level to beat, even on Hard difficulty.